This invention relates to an information processing apparatus and, more particularly, to a multi-window display controlling device of a data processor for controlling various types of operations by means of a cursor, which is moved by a pointer device such as a mouse.
Information processing apparatuses having a multi-task/multi-window system are well-known. In such an apparatus, a cursor is displayed on a CRT screen, for example, and is moved to a predetermined location on the screen by means of a pointing device such as a mouse, to designate a desired processing operation.
In the information processing apparatus, if the cursor is moved to a specific area on the CRT screen, the shape of the cursor is changed to show the operator the command that will be executed when the mouse is operated. For example, when a line is typed and echoed onto the screen, the cursor is shaped like a "pen." To move a displayed object, the cursor is shaped like a "pincette."
Indicating a command by an exact shape at the specific cursor location makes it easy for an operator to understand the operation performed by the command.
In such a multi-task/multi-window apparatus, a plurality of windows are displayed on one screen of the CRT display and tasks corresponding to those windows are executed concurrently. If the cursor shape is changed every time the cursor is moved to a specific location in each window in such a multi-task/multi-window data processing apparatus, the operator is often confused.
In this type of data processing apparatus, windows frequently partially overlap. If the cursor shape is changed when the cursor is below an overlapping window, the changed shape of the cursor does not present any effective information to the operator because the cursor is in the limited part of the window not being displayed. Additionally, every time the cursor is moved on the CRT screen, the system must determine the position of the cursor relative to the various to the various window regions resulting in increased response time for the system.